How severe is CVE-2026-59939?

CVE-2026-59939 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-59939 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-59939?

CVE-2026-59939 affects Httplib2 Project Httplib2. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-59939?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-59939 published?

CVE-2026-59939 was published on 2026-07-08 and last updated on 2026-08-20.

CVE-2026-59939

CVE-2026-59939 is a high-severity vulnerability in Httplib2 Project Httplib2 with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-409.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-409
Affected product: Httplib2 Project Httplib2
Published: 2026-07-08
Last modified: 2026-08-20

Description

httplib2 is a comprehensive HTTP client library for Python. Prior to 0.32.0, httplib2 performs unbounded decompression of HTTP response bodies encoded with Content-Encoding: gzip or deflate in _decompressContent in httplib2/init.py, allowing a malicious or compromised HTTP server to return a small compressed payload that expands to an arbitrarily large size in memory and causes MemoryError or OOM-kill in the client process. This issue is fixed in version 0.32.0.

Frequently asked questions

What is CVE-2026-59939?: httplib2 is a comprehensive HTTP client library for Python. Prior to 0.32.0, httplib2 performs unbounded decompression of HTTP response bodies encoded with Content-Encoding: gzip or deflate in _decompressContent in httplib2/init.py, allowing a malicious or compromised HTTP server to return a small compressed payload that expands to an arbitrarily large size in memory and causes MemoryError or OOM-kill in the client process. This issue is fixed in version 0.32.0.
How severe is CVE-2026-59939?: CVE-2026-59939 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-59939 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-59939?: CVE-2026-59939 affects Httplib2 Project Httplib2. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-59939?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-59939 published?: CVE-2026-59939 was published on 2026-07-08 and last updated on 2026-08-20.

References

Affected products (1)

cpe:2.3:a:httplib2_project:httplib2:*:*:*:*:*:python:*:*

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